High frequency mechanical impact (HFMI) is widely used in the field as a reliable and efficient repost-weld treatment. In order to evaluate the fatigue life of steel welded joints treated by HFMI under different stress ratio R and material yield strength fy, extensive fatigue test data were re-analyzed using the notch stress approach combined with SWT (smith-watson-topper) and Walker models. The results reveal that the relationship between the fatigue grades FAT, R and fy of the joints under nominal stress system can be expressed by FAT = 0.1 fy + M(R). Under the notched stress system, for joints made of the same material loaded under different R values, both models can be used to predict fatigue life, but the Walker model has higher accuracy. For joints of various materials with different R values, SWT model has a fixed form and can comprehensively consider the influence of R and fy. Based on this, the survival rate PS = 97.7% of the S-N curve with FAT = 325 MPa and slope m = 6.5 is obtained. The research will directly support the fatigue assessment and anti-fatigue design of engineering structures.
HU Xin
,
LI Yanqing
,
HUANG Jinhao
. Discussion on fatigue evaluation models of steel welded joints treated by HFMI[J]. Transactions of The China Welding Institution, 2022
, 43(3)
: 80
-86
.
DOI: 10.12073/j.hjxb.20210703003
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